The Silent Ambassador

Oren Vasquez took the hardest ambassadorship in the solar system because no one else would. The Takhi do not speak out loud, and to them, humans are not persons. Just furniture with a title. The only Takhi who treats him as anything else is Sivesh, an archivist too low-caste to matter, assigned to translate the furniture. He is not supposed to touch Oren. He does. And once he starts, neither of them stops. When the council moves to sever ties with Earth entirely, Oren has to argue for a planet's personhood using evidence from the one room he should never have been in, given to him by the one alien he should never have touched.